Biochemical Differentiation of Alcoholic and Non-Alcoholic Fatty Liver Disease: A Comparative Study of Lipid Profile and De Ritis Ratio in Ultrasonography-Diagnosed Patients

Abstract

Fatty liver disease encompasses two clinically overlapping but pathophysiologically distinct entities: alcoholic fatty liver disease (AFLD) and non-alcoholic fatty liver disease (NAFLD). While abdominal ultrasonography remains the standard first-line imaging modality, it cannot differentiate between these two conditions, making non-invasive biochemical markers essential - particularly in resource-limited settings where liver biopsy and advanced elastography are often inaccessible. This comparative cross-sectional study enrolled 146 adult patients (≥18 years) with ultrasonography-confirmed fatty liver disease at Nepal Medical College and Teaching Hospital between July and December 2025; 59 (40.4%) were classified as AFLD and 87 (59.6%) as NAFLD. Serum AST, ALT, total cholesterol (TC), triglycerides (TG), HDL, and LDL were measured, and the De Ritis ratio (AST/ALT) was calculated. The Shapiro-Wilk test confirmed non-normal distribution for most variables; the Kruskal-Wallis and Mann-Whitney U tests were used for group comparisons, with multivariable logistic regression to identify independent predictors. The De Ritis ratio showed a significant bivariate association with AFLD (χ² =5.78, p =0.016; Cramér’s V =0.199) but did not retain independent significance on multivariable analysis (adjusted OR =1.30, 95% CI: 0.55-3.05, p =0.545). Total cholesterol (adjusted OR =1.05, 95% CI: 1.03-1.06, p <0.001) and triglycerides (adjusted OR =0.96, 95% CI: 0.92-0.99, p =0.012) were the key independent discriminators. ROC analysis confirmed excellent diagnostic accuracy for TC (AUC =1.000) and LDL (AUC =0.808) in identifying AFLD. Lipid profiling, combined with clinical history and ultrasonography, offers a practical and cost-effective non-invasive approach to differentiating AFLD from NAFLD in resource-constrained clinical settings.